Laundry apparatus



July 4, 1961 2 Sheets-Sheet 1 Filed March 28. 1958 July 4, 1961 v. WEBER ErAL 2,991,342

LAUNDRY APPARATUS Filed March 28, 1958 2 Sheets-Sheet 2 United States Patent O 2,991,342 LAUNDRY APPARATUS Victor Weber, Greensburg, land Francis S. Genbauife, Irwin, Pa., assignors to Robertshaw-Fulton Controls Company, Richmond, Va., a corporation of Delaware Filed Mar. z8, 195s, ser. No. 724,712 3 Claims. (Cl. 200-140) This invention relates to automatic laundry machines of the type designated as clothes driers and the combination clothes washer-driers.

An object of this invention is to insure automatically the required time for drying substantially any type of material in a laundry machine.

Another object of this invention is to condense moisture from the exhausted air of a laundry machine before recirculating the air.

Another object of this invention is to utilize a stream of condenser water for removing the lint from the exhausted air of a laundry machine.

This invention has another object in that the temperature differential between the entry and discharge of a condenser fluid is utilized for controlling a laundry machine.

In the preferred embodiment of this invention, a laundry machine having a rotatable drum is provided with a blower and heater for circulating air through the drum and with a condenser positioned adjacent an exhaust opening to condense moisture from the circulating air. The condenser is cooled by a stream of cooling lluid which is intersected by the exhausted air to remove lint and additional moisture from the exhausted air.

Control means are provided for controlling operation of the drier, this means comprising a pair of expansible elements, one of which is responsive to the temperature of cooling iluid at its entry and the other of which is responsive to a temperature of the mixed fluid at its discharge. An operative connection is provided between the expansible elements whereby the position of one of such expansible elements is indicative of a temperature differential of the cooling iluid and mixed iluid. An

operative connection between the Iindicating expansible element and control means causes actuation thereof upon a change in the temperature differential for controlling energization of the heating means for the circulated air.

vTimer operated means including a plurality of switches are provided for initiating operation of the drier and to effect a predetermined rundown time after de-energiza- 'tion of the heating means.

Other objects and advantages will become apparent vfrom the following description taken in connection with v'the accompanying drawings wherein:

FIG. 1 is a sectional view in schematic form of a washer-drier laundry machine and control means therevfor embodying this invention;

FIG. 2 is a section taken along the line II-I-I of FIG. l;

4drum or container 12 of generally cylindrical configuraxtion is rotatably mounted by any suitable means (not shown). A shaft 14 extends from one end of the drum 1 2 in axial alignment therewith and carries a pulley 16 'thereon which serves as a means for imparting rotative `movement to the drum 12. The pulley 16 is driven by electric motor 18 which is suitably xed to the housing 10 and provided with a pulley 20 connected to the pulley 16 1by means of a flexible belt 22.

The housing 10 defines an annular chamber 24 between the interior wall thereof and the outer periphery of the drum 12. A tubular conduit 26 has one end opening into the wall of the housing 10 to form an air outlet 27 for the chamber 24 and the other end opening into another wall of the housing 10 to form an air inlet 28 for the chamber 24. The air inlet 28 introduces heated air directly into the open end of the drum 12. The periphery of the drum 12 is perforated by a plurality of ports 30 for establishing communication between the chamber 24 and the interior of the drum 12.

During a drying operation, heated air is supplied to the interior of the drum 12 by means of the conduit 26 and exhausted through the por-ts 30 into the chamber 24 from which the air is recirculated through the conduit 26 to the drum 12. To accomplish this, an elec* trically operated blower 32 is positioned in the end of the conduit 26 adjacent the outlet 27 of the chamber 24 and suitably supported on the wall of the conduit 26. An electric heating element 34 is positioned in the conduit 26 adjacent the blower 32 to heat the air circulated thereby. Thus, when the motor 20, blower 32 and heating element 34 are energized, the air will be drawn from the chamber 24, heated in the conduit 26 and recirculated -into the rotating drum 12. When the air flows past the heating element 34, it will be heated thereby to pick up any moisture contained in the clothes being tumbled in the drum 12.

Means are provided for condensing moisture in the moisture-laden `air exhausted from the ports 30 so that the exhausted air may be recirculated through the conduit 26 and drum 12. To this end, a curved bailletype condenser plate 38 is positioned within the chamber 24. The plate 38 has one end thereof fixed to the upper portion of the wall of the housing 10 and the other end thereof terminating adjacent the blower 32. The center of the curvature of the curved portion of the plate 38 coincides with the longitudinal axis of the drum 12 whereby such curved portion is spaced parallel to the surface of the drum 12.

In order to supply a source of cold water to the condenser plate 38 to cool the same, the housing 10 is provided with an opening 40 in the uppermost portion thereof over which a cold water reservoir housing 44 is seated on the housing 10. The housing 44 defines a chamber 46 which communicates with the opening 40 and communicates with a source of cold water (not shown) by means of a pipe 48 suitably threaded within the end of the housing 44.

When the pipe 48 is connected to the source of cold water (not shown), the chamber 46 will be filled with cold water as indicated in FIG. l of the drawings. Accordingly, a predetermined amount of cold water will llow through the opening `4l), strike the baille 38 and llow over the convex surface thereof to the bottom of the housing 10 by gravity whereby a curtain of water ilows past the outlet 27. The air exhausted from the chamber 24 by the blower 32 is drawn through the water curtain whereby additional moisture and lint is removed from the exhausted air.

The cool water thus flowing over the convex surface of the baille 38 will cool the same. Accordingly, the moisture in the air emitted from the ports 30 in the drum 12 will now be condensed on the concave surface of the baille 38. It Will be apparent that air emitted from the ports y30 Will necessarily contact the concave surface of the baille 38 or the Water curtain formed at the lower edge of the baille 38 by water falling to the bottom of the housing 10. Thus, substantially all of the moisture contained in the exhaust air will be condensed and the air conditioned for recirculation by the blower 32.

Any moisture condensed on the concave surface of the plate 38 will flow to the lower end of the yplate 38 and become mixed with the cooling water in the water curtain. Since the temperature of the air circulated into the drum 12 is high due to the previous heating by the element 34, there will be a substantial temperature differential between the water in the chamber 46 and the water at the bottom of the housing due t0 the heating eiect of the air owing over the bale plate 38 and through the water curtain, and due to the mixing of the cooling water with the warm condensed moisture.

The housing 10 is provided with an opening 52 in the bottom thereof to drain the lint and the mixed cooling water and condensate from the housing 10. A circular plate 54 of smaller diameter than the opening 52 is supported centrally of the opening 52 to define an annular passage between the plate 54 and the edge of the opening 52. A housing 56 is supported on the bottom of rthe housing 10 to provide a chamber reservoir 58 for collecting a quantity of the water owing from the opening S2. A drain pipe 60 is connected to the bottom of the housing 56 in alignment with the opening 52.

To maintain a predetermined height of liquid in the housing 56, a hollow tubular member 62' is xed to the bottom wall of the housing 56 concentric with the opening defined by the pipe 60. The upper end of the member 62 is positioned slightly below the opening 52. Thus, water will not iiow out of the chamber 58 until the height or depth of the water in the housing 56 exceeds that of the tubular member 62. Accordingly, a predetermined quantity of water is always maintained in the chamber 58 as indicated in FIG. 1. Since the tubular member 62 is of smaller diameter than the disc 54, water cannot iiow directly from the housing 10 into the tubular member 62 for a purpose which will later become apparent.

The amount of moisture contained in the air emitted from the drum 12 will depend upon the amount of moisture in the clothes being dried. Accordingly, as the clothes become dry, less moisture will be condensed on the concave surface of the plate 38 and in the water curtain. Since the temperature of the cooling water is increased by mixing with the condensate from the exhaust air, it is apparent that the temperature of the water owing into the reservoir 58 will decrease as the condensation decreases as a result of the clothes becoming dry. It has been found that a predetermined decrease in this temperature differential is a positive indication that the clothes are dry.

Means responsive to the temperature dierential between the water in the reservoir 46 and the water in the reservoir 58 are provided for controlling the operation of the drying apparatus. This means includes a control device having a casing 66 which may be supported on the housing 10 or on another suitable supporting structure. The casing 66 is made of any suitable insulating material and has a generally rectangular conguration with an open upper end which is closed by a cover plate 68. A generally U-shaped bracket 70 (FIGS. 2 and 3) has a pair of downwardly extending legs 72, 72 on each side of a medial portion 74 which is fixed to the under side of the cover plate 68.

A pivot pin 76 is mounted in a pair of oppositely disposed hook-shaped bearing supports 78 formed in the lower ends of the legs 72, 72 respectively. A mounting lever 80 of generally U-shaped conguration is pivoted at one end on the pin 76 and carries on the other end thereof a temperature responsive means in the form of an expansible and contractible diaphragm 82 which has an operating button 84 projecting therefrom. The interior of the diaphragm `82 is in communication with a capillary tube 86 which extends exteriorly of the housing 66 Ifor communication with a bulb sensing element 88 positioned within the chamber v46 to sense the temperature of the water therein. As is well known in lthe art, the temperature responsive means contains a liquid which expands upon the bulb element 88 being heated to eiect movement of the operating button 84.

The cover plate 68 is provided with an aperture 91 which receives a suitable tool for rotating a screw 92 which is threadedly mounted in one end of a calibration lever 94. A pair of oppositely disposed guide slots 96, 96 formed in the upper ends of legs 72, 72, respectively, of the lever 70 receive a pair of oppositely disposed ears 98, 98 formed on the other end of the lever 94 for pivotally mounting the same on the ylever 70. The screw 92 abuts the supporting end of mounting lever y80 whereby the same is normally restrained against clockwise pivotal movement and thus limits the upward displacement of the temperature responsive means 82. Rotation of the screw 92 adjusts this limit by effecting movement of the mounting lever about the Ipivot pin 76. The lever 94 is engaged by one end of an adjusting screw 100 which is threaded in the cover plate 68 and has the other end thereof extending exteriorly of the housing 66 to receive a manually operable dial 102. It will be apparent to those skilled in the art that rotation of the dial 102 will adjust the axial position of the screw and serve to vary the angular position of the levers 94 and 80 for changing the position of the diaphragm 82 with respect to the pivot pin 76.

To enclose the threaded portion of the adjusting member 100, a cup-shaped member 104 is provided with a suitable bore in the bottom wall thereof through which the member 100 projects. A pair of end flanges extend outwardly from the cup-shaped member 104 and are `secured to cover plate 68 by any suitable -means (not shown). An abutment 108 extends lfrom the cup-shaped member 104 and is adapted to be engaged by an arm 110 attached to the dial 102. The arm 110 may be formed by bending a suitable pin and embedding or otherwise xedly connecting one end thereof in the underside of the dial 102. It will be apparent that the arm 110 will engage opposite sides of the abutment 108 upon rotation thereof to establish a limited range of rotation of the dial 102.

An offset lever 114 is provided with a pair of spaced parallel portions 116, 118 oppositely disposed on different levels and connected by a medial portion 120 which is pivotally mounted on the pin 76 for actuation of the lever 114 by the operating button 84. As is illustrated in FIG. 3, the portion 116 is on a level substantially aligned with the pin 76 and underlies the diaphragm 82 to engage the button 84. A spring 122, which is mounted in compression between the bottom of a cup-shaped recess 123 within the cover plate 68 and the upper side of the lever portion 118, maintains lever portion 116 in biased engagement with diaphragm button 84. The biasing force of the spring 122 is thus transmitted by the lever 114 through the diaphragm `82 to the levers 80, 94 to maintain the same in engagement with the screw 92 and threaded member 100, respectively.

A second thermally responsive means is carried by the lever 114 for rotation therewith upon expansion and contraction of the diaphragm 82. This means comprises a diaphragm 124 similar to the diaphragm 82 and which is disposed on the lower side Yof the lever portion 118 and has an operating button 126 movable along an axis substantially parallel to the direction of movement of the button 84.

The interior of the diaphragm 124 is in communication with a capilltary tube 132 which extends exteriorly of the casing 66 for communication with a bulb element 134 which is positioned in the reservoir 58 to sense the temperature of the water therein.

In the structure of the control device thus far described, the operating button 84 is positioned by variations in temperature of the cold water within the reservoir 46 and the operating button 126 is positioned by variations in temperature of the water in the reservoir 58. It will be apparent however that since'the diaphragm 124 is carried by the lever 114, any movement of the button 84 will also cause movement of the button 126. Accordingly, an increase in the temperature of the water in reservoir 58 will cause expansion of the diaphragm 124 and downward movement of the button 126. However, should the temperature of the water in the reservoir 46 increase by an equal amount, the diaphragm 82 will expand causing an equal downward movement of the button l84 which rotates the lever 114 and moves the diaphragm 124 upward.

Thus, when the bulbs 88, 134 are subjected to an equal temperature increase, the resulting position of the operating button 126 with respect to the pivot pin 76 will not change. However, if the temperature increases to which the bulbs `88, 134 are subjected are unequal, the movementsof the operating buttons 84, 126 will also be unequal. In this case, the button 126 will be moved relative to the pivot pin for a distance proportional to the difference of the temperature increases sensed by the bulbs 88, 134, respectively.

-Control means in the form of switch means are positioned in the lower portion of the casing 66 to be actuated by the operating button 126 upon movement thereof. To this end, a pair of parallel terminal strips 138, 140 extend through the wall of the housing 66 and are provided with a pair of contacts 142, 144 mounted on the interior ends thereof, respectively.

A movable contact 146 is cooperable with the contacts 142,144 and is carried on a movable end of a movable contact arm indicated generally by the reference numeral 148. The other end of the contact arm 148 is clamped by a plate 154 in engagement with a terminal strip 150 which is seated on an abutment 152 formed on the casing 66,.

A reinforcing tongue 156 is attached to a portion of the contact arm 148 adjacent the contact 146. Snap action movement is imparted to the reinforcing tongue 156 and contact 146 by means of an overcenter U-shaped spring 158 mounted between two knife edges 160, 162 formed 0n the thin section of the contact arm 148.

The tongue 156 is positioned in a slot 166 of an actuating member 170 which is of generally rectangular configuration and has one end thereof slidably mounted in a slot 172 formed in a projection 174 on the bottom wall of the casing 66. A spring 176 encircles projection 174 and is mounted in compression between the bottom wall of the casing 66 and a spring retainer 178 iixed to the actuating member 170.

The upper end of the actuating member 170 is carried on one end of a lever 1182, the other end of the lever 182 being pivotally mounted on an abutment 184 on the wall of the casing 66. A second lever 186 overlies the lever 182 and carries an insulating member 188 on one end thereof which engages a raised portion 190 on the lever 182 adjacent the pivot point thereof. The other end of the lever 186 is pivotally mounted on a fixed knife edge 192 positioned adjacent the diaphragm 124. The operating button 1,26 of the diaphragm 124 engages the lever 186 adjacent the knife edge 192, the lever 186 being biased in a clockwise direction by the biasing force of the spring 176 transmitted by the actuating member 170 and lever 182,.

It will be apparent that downward movement of the operating button 126 will effect downward deflection of the levers 182, 186 which multiply movement of the button 126 and effect downward movement of the actuating member 170 against the bias of the spring 176. In the position shown, the tongue 156 engages the upper edge of the slot 166 and a force is exerted by the spring 158 on the tongue 156 which tends to pivot the tongue 156 on the upper edge of the slot 166 to hold the contact 146 into engagement with the contact 144 as shown. However, downward movement of the actuating member 170 will displace the tongue 156 downwardly to the overcenter position thereof. When the tongue 156 and spring 158 pass the overcenter position the force exerted by the spring 158 `reverses in direction causing a snap action to move the contact 146 into engagement with the contact 142 and displace the tongue 156 into engagement with the lower edge of the slot 166.

A control circuit for this laundry machine is illustrated in FIG. 4 wherein the relative positions of the contacts are shown in a de-energized state. The operation is cornmenced by a timing device, indicated generally at 196, which includes a timer motor 197 that has a cam shaft (not shown) for selectively actuating contacts 198, 200, 202, and 204. The cam shaft simultaneously closes the contacts 198, 200, 202, and 204 and sequentially opens the same with contacts 198 being opened first, contacts 202 are opened next, and contacts 200 and 204 are finally opened simultaneously. The operation is initiated by manual rotation of the timer dial to a predetermined position so that contacts 198, 200, 202, and 204 are actuated to a closed position by the timer cam shaft.

Thus, the heater 34 is energized by an electrical circuit traced from line L1 through contacts 198 and heater 34 to line L2; the blower 32 is energized by a circuit traced from line L1 through contact 200 and blower 32 to neutral ground line N; driving motor 18 is energized by a circuit traced from line L1 through contacts 200 and a parallel circuit through driving motor 18 to neutral ground line N; and the timer motor 197 is energized by a circuit traced from line L1 through contacts 144, contacts 204, and timer motor 197 to neutral ground line N.

The original temperatures of the cool water in chamber 46 and the drain water in chamber 58 are substantially equal so that the relative positions of the operating elements of the temperature differential control device are as shown in FIG. l with contacts 142 open and contacts 144 closed.

After a short stabilization period, the moisture laden air from the damp clothes circulates against the condenser baiile 38 and through the water curtain and the condensed moisture drains into the warm water reservoir chamber 58. A temperature diierence then exists between the cold tap Water in chamber 46 and the warm drain Water in chamber 58 and results in actuation of the temperature differential control device to close contacts 142 and open contacts 144. Once sufiicient time has elapsed to ensure stable drying conditions, the timer cam shaft opens the timer contacts 198, which operation allows closed contacts 142 to carry current to the heater 34. At this point of the operation, contacts 144 are opened, however, contacts 202 are closed which allows the timer motor 197 to continue running. The continued rotation of the timer cam shaft for a predetermined time cause contacts 202 to be opened shortly after contacts 198 are opened; this opens the parallel circuit to the timer moto-r 197 to stop the same. However, the heater 34, blower 32 and drive motor 18 remain energized to continue the drying operation.

This drying action continues by circulating heated air through the tumbled clothes until the temperature difference between the cold tap water and the warm drain water drops to a predetermined lower value, indicating a dry load, at which time the contacts 142 are opened and contacts 144 are closed. The heater 34 is tie-energized by the opening of contacts 142 and the timer motor 197 is energized again by the closing of contacts 144. The load of clothes is then allowed to cool by circulating unheated air through the tumbled clothes for a time sufiicient to allow safe handling of the heated clothes; the expiration of the predetermined cooling time as indicated by the timer opens contacts 200 and contacts 204 which are interlocked for simultaneous actuation, and thus de-energizing the blower 32, the driving 7 motor 18, and the timer motor 197 to complete the drying cycle.

inasmuch as the preferred embodiment of this invention is subject to many modifications, structural variations and reversal of parts, it is intended that the drawings and the above description be interpreted as illustrative and not in a limiting sense.

We claim:

1. In a control device for a laundry machine or the like, the combination comprising a casing, control means in said casing operable between controlling positions, a pin mounted in said casing to form a iixed pivotal axis, a lever having a central portion pivotally mounted on said pin and having oppositely disposed ends, a mounting element having a supporting end and an opposite end pivotally mounted on said pin, a lirst temperature responsive means carried by the supporting end of said mounting element and having a first movable member engaging one end of said lever, a second temperature responsive means carried by the opposite end of said lever and havving a second movable member, an operable connection between the second movable member and said control means for actuation thereof, yieldable means mounted in compression in said casing to bias said lever whereby the rst movable member maintains engagement with the said one end ot said lever, said lever being pivoted against the bias of said yieldable means by displacement of the rst movable member in one direction in response to expansion of said -irst temperature responsive means whereby the second movable member is displaced in an opposite direction, and said second movable member being displaced in the same direction as the rst movable member in response to expansion of said second temperature responsive means whereby the resultant movement of said second movable member is dependent upon a differential expansion between the tirst and second temperature responsive means.

2. The combination as recited in claim l wherein a calibration lever is pivotally mounted in said casing and carries abutment means engaging the supporting end of said mounting element, and an adjusting screw is threadedly mounted in said casing to abut said calibration lever and being rotatable to pvot the same relative to the supporting end of said mounting element.

3. The combination as recited in claim 2 wherein said abutment means comprises a second adjusting screw threadedly mounted on said calibration lever and being rotatable to pivot said mounting element about the xed pivotal axis of said pin.

References Cited in the tile of this patent UNITED STATES PATENTS 2,297,706 Jehle et al. Oct. 6, 1942 2,431,801 Gibson Dec. 2, 1947 2,536,83l Allan Ian. 2, 1951 2,720,087 Erickson Oct. 11, 1955 2,743,533 Smith May l, 1956 2,778,575 Kucera Ian. 22, 1957 2,849,185 Keyes Aug. 26, 1958 2,849,577 Pfeiter Aug. 26, 1958 2,855,486 Weber et al. Oct. 7, 1958 

